Rotary air cleaner



y 1943- R. A KELSEY ET AL 3 ROTARY AIR CLEANER Filed July 5, 1940 2 Sheets-Sheet 1 J H r 7 4 20 J1 12 J 10 I 7 6- v .15 i 261 8 J6 i 2,2, 11w TORJ 5 BOBs TA, ELSE),

BY like/2v WRIGHT,

. A Tromva m 1 R. A. KELSEY ET AL ROTARY AIR CLEANER Filed Jul 5, 19 10 2 Sheets- Sheet 2 4 x a r S 5 R Y T m? ZR a m N W T 10 A v e 2 2 a Patented July. 20, 1943 2,324,629 ROTARY AIR CLEANER Robert A. Kelsey and Harry Wright, San Diego,

- Calif., assignors, by mesne assignments, to Airmax Corporation, San Diego, Calif., a corporation of Nevada Application July 5,1940, Serial No. 344,090

' 9 Claims. (01. ma -9) This invention relates broadly to devices for cleaning gases, particularly air. A chief field of use of th invention is in cleaning the air supply of internal combustion engines, although it is in no sense limited to this particular use, as will appear hereinafter.

A general object of the invention is to provide a gas cleaner or the wetted screen type, that is simple and inexpensive, while having a high.

cleaning efficiency and being reliable in operation.

A more specific object is to provide a gas cleaner of the wetted screen type having a particularly simple and eifective meohanism for circulating the wetting liquid over the screen.

A feature of the invention is a. gas cleaner of the wetted screen type, in which the wetting liquid is circulated over the screenin response to centrifugal force developed by a rotating element.

Other specific objects and. features of the invention will appear from the following detailed description of certain specific embodiments of the invention, as illustrated in the accompanying drawings, in which V Fig. 1 is a plan view, with parts broken away, of one embodiment of the invention, in which the rotary element is driven by the air to be cleaned;

Fig. 2 is an elevation view, partly in section, of the cleaner shown in Fig. 1;

Fig. 2A is an enlarged detail sectional view of a portion of the structure shown in Fig. 2;

Fig. 3 is a plan view, with parts broken away,

of the upper portion of a modification of the cleaner shown in Figs. 1 and 2, adapted for cleaning air supplied to the cleaner under pressure;

Fig. 4 is a sectional view in Fig. 3;

Fig. 5 is a detail elevational view, partly in section, showing a modification of the structure shown inFigs. 1 and 2; and

the plane I IV'of which the air is drawn. This filter element 6 consists of a mass of metal turnings I, or similar material, supported between a lower screen 8 and an upperscreen 9. In addition to the lower and upper walls 8 and 9, respectively, the filter element 6 has an outer peripheral wall III which is spaced inwardly from the peripheral wall II of the casing I, but has a circumferential row of holes I2 therein. an inner edge wall I3 which extends downwardly andinwardly to form a converging skirt I4, extending almost to the bottom wall 5 of the case. The upper wall 9 extends inwardly a short distance past the upper edge of the wall I3 to form an overhang I5. The inner wall I3 has a circumferential row of holes I6 therein.

The whole screen or filter structure so far described is attached at its outer edge to thelower edge of a dome member H w h is secured to a central hub III, the latter bei g in turn secured, as by a set screw I9, to a central-shaft 20, the latter being rotatably sigaported by upp a lower ball bearings 2| a 22, respectively. The upper ball bearing 2I is mounted in the cover 2 and the lower bearing member 22 is mounted in a spider 23 having a rim 2-! slidably fitted within the discharge pipe 4.

It will be apparent from the foregoing description, that the entire filter element, together with the dome I1, is freely rotatable as a unit within the-casing I. A knob 25 may be mounted on the upper end of' the central shaft2ll, exterior of the bearing 2I, to give a visual indication of the rotation of the rotatable member and permit manual testingto' determine if the member is Fig.6 is a schematic vertical sectional view showing still another modification of the invention.

Referring first to Figs. 1 and 2, the cleaner therein disclosed comprises a stationary casing I of approximately cylindrical shape, adapted to be closed at the top by a detachable cover 2, the casing and the cover defining a chamber into which air enters through an annular row of louvers -3 in the cover 2, and from which it discharges through a central discharge pipe 4 which extends downwardly through the center of the bottom wall 5 of the casing I.

Positioned within the casing I is a' rotating element including a filter element 6, through freely rotatable.

The lower portion of the chamber within the casing I constitutes a cleansing liquid (which will b hereinafter referred to as oil) reservoir. The oil reservoir is separatedfrom the upper,

outer portion of the chamber by a horizontal annular partition wall 26 which is supported at its outer edge by a bead 21 pressed into the peripheral' wall II of the casing. The wall 25 is also supported adjacent its inner edge by a cylindrical ,f bafiie plate 28 which is secured at its upp edge' to the wall 26, the lower edge of bailie 28 rest:

ing on the bottom wall 5. The baffle 28 is provided with a circumferential row of holes 29 near its lower edge for the fiow of oil therethrough. The oil level will normally be adjacent the partition wall 26, as indicated at 2BI. H

In operation, the rotary element is rotated or spun at suflicient speed (by means to be described later) to carry oil from the reservoir up- The filter element 6 also has I wardly along the inner surface of the inclined walls I4 and i3 by centrifugal force through the hole l6 into the inner edge of the filter element 6. The oil is then urged outwardly through the filter element by the same centrifugal force which increases in magnitude from the inner edge to the outer edge of the filter element; since the centrifugal force, coupled with the force of gravity, acts outwardly and downwardly, whereas the filter element 6 is inclined upwardly and outwardly, part of the oil leaves the under-surface of the filter element and is thrown outwardly through the air stream which moves down through the inlet louvers 3 past the edge of the dome I1 and then flows inwardly and upwardly through the filter 6 and into the discharge pipe 4. Some-of the finer particles of oil are carried back into the filter by the air current. Other, larger particles strike the peripheral wall II or the partition wall 26 and drain back into the reservoir across the inner edge of the partition wall 26.

Of course the flow of air through the filter 6 also tends to carry oil upwardly through the filter,'counteracting to a certain extent, the tendency of th oil to be thrown out of the lower surface of the filter element by centrifugal force and gravity. As a result, some of the oil traverses the full length of the filter to the holes l2, from whence it is thrown directly across the air stream at the narrowest point of the latter, where the air is travelling at highest velocity. As a result, a substantial portion of this oil thrown out through the holes I2 is caught by the air stream and carried back into the filter element 6.

A a. result of the oil particles being thrown into the air stream before it enters the filter G, a substantial number of the particles of dust in the air are wetted by the oil particles so that they either drop out or the air stream by virtue of their weight, onto the partition wall 26, or are immediately deposited upon the wet surface of the filter element during passage of the air therethrough. Of course additional dust particles that were not wetted by the oil prior to the entry of the air into the filter element, are deposited on the wetted surface of the filter.

A few oil particles may be carried by the air completely through the filter element 6, but most of such particles will be thrown out of the air stream onto the dome ill by virtue of the change in the direction of the air to get into the open, upper end of the discharge passage 6. Any oil particles deposited on any part of the undersur-- -tace of the dome I1 are thrown outward by centrifugal force to the lower edge of the dome, from whence they escape through the holes i2 along with oil that reaches the holes i2 directly through the filter 6.

By virtue of the relatively powerful centrifugal forces acting upon the oil permeating the filter element 6, a relative rapid fiow of oil is produced through the filter, rapidly carrying away the accumulated dust deposits and preventing any clogging of the filter element. The dust and dirt collected by the oil accumulates in thebottom of the oil reservoir.

In the particular modification described in Figs. 1 and 2, rotation of the filter element is produced by the air entering the louvers 3 in response to suction applied to the discharge pipe 4. Thus the pipe 4 may be connected to the intake pipe of an internal combustion engine, the suction of which draws air through the cleaner. The motor element proper is a fan 30 secured to the dome i! and having vanes or blades 3| positioned immediately below the louvers 3 and inclined in a direction opposite to the direction of inclination of the louvers 3. The inclination of the louvers deflects the entering air so that it moves in a helical path instead of straight down. This air, as it passes through the blades 3i, produces a torque which spins the fan and the rotatable filter element secured thereto.

The energy for rotating the filter element is, of course, derived from the suction-producing device connected to the discharge pipe I and causes v a pressure drop through the entire unit that may be objectionable in some instances. In this event, it may be desirable to rotate the filter element from an externalsource of power. Thus an electric motor 32 may be mounted on the cover plate 2, as shown in Fig. 5, and have its shaft directly connected to, or integral with, the shaft 20. The motor casing may be detachably supported in a clamp base 33 provided on the cover plate. In the particular construction shown in Fig. 5, the shaft 20 is journalled in a plain bearing in the base 32, instead of in a ball bearing as shown in Fig. 2. This is permissible because where an external source of power is employed for positively rotating the rotatable ele-- ment, it is not so important to reduce friction to a low value. The motor 32 may supply only sufficient power to rotate the filter element and the fan 30 (Fig. 2), may be eliminated. On the other hand, the fan 30 may be retained even when the motor is used to produce a supercharging effect to actually produce a pressure increase in the air passing through the filter.

There are some applications in which it is desired to clean air under pressure. In such instances the cleaner structure shown in Fig. 2 may be employed with a. manifold for delivering the air under pressure through the fan 30. Such a construction is shown in Figs. 3 and 4, in which the cover plate 2' is in the form of a casing having a curved input manifold 40 adapted to be connected at its input end I to a. source of air under pressure. The air is discharged from the manifold 40 through apertures 42 immediately above the blades ll of the fan. The remainder of the, construction is identical with that of Fig. 2, and the rotatingelement is spun by the force of the entering air, exactly as in the case of the structure shown in Fig. 2.

One application of the modification shown in Fig. 4 is a. cleaner for dirt-laden air from a vacuum cleaner, or the like, the device being substituted for the usual filter bag.

In all of the structures disclosed in the drawings, the cover and the rotating element are removable from the case i as a unit, to permit removal of dirt from the chamber in the bottom of the case i. Thus the upper end of the shaft 20 of the rotatable element is rotatably supported from the cover, and the.ring 24 on the spider 23, which radially supports the lower bearing, is freely slidable through the discharge pipe 4 so that when the cover is lifted straight up the rotatable element comes with it. Thereafter the partition plate 26 and the baille plate 28 may be lifted out as a unit, leaving the bottom of the easing fully accessible for cleaning. The cover may be normally secured in place on the case I by any desired means. Thus it may be made to fit snugly by friction on the top of the casing or any well-known fastening expedients, such as interrupted screw threads, may be utilized.

The modification of the invention shown in sufficient to spin having a skirt 51. pool of skirt 5'! has adjacent its upper edge louvers G Thelower end of this skirt dips in a formed integrally therewith and extending inwardly and downwardly from its outer edge,

oil 58 in the bottom of the case 50. The

vention' certain specific embodimentsithereoi Although for the purpose of explainingthe inhave been described in detail, it is to be a dot stood that various change from theparticular construction shown can be made without departing from .theinvention, which is tobe limited only as set forth in the appended claims.

11A gas cleaner comprising a stationary casing having a central gas conduitextcnding downwardly through the bottom wall therebf and'de finingtherewith an annular chamber forwcontaining a pool of liquid, arotor in the form of an inverted cuphaving, its edge dipping into said liqfor thepassage of the air to be cleaned andthe peripheral wal15l of the casing has louvers 6! therein, which are juxtaposed to the louvers 5!! butangled in the opposite direction so that currents of air passing through the two sets of louvers, ,apply a torque to the rotating element In response to the sp nning of the rotary member, oil from the pool 58 is carried by centrifugal force up along the innersurface of the skirt 51 to the louvers 60, where the oil is caught in the air stream and carriedinwardly with the air in the form of small droplets, Positioned inwardly of the rotary member is a stationary member having a closed top wall 62 spaceda short distance below the disc 55 and having a skirt 63 of fine mesh screen wire. The skirt 63 is positioned parallel to and a short distance within the rotating skirt 5! but unl ke the latter, extends clear to the bottom wall 52 of'the outer case. The dropletsof oil carried by the air stream are impinged upon the screen 53 and are broken up and subdivided into finer form. A part of 'theoil is carried through the screen in finely divided form, and a portion ofthe oil may. of course, accumulate on the screen 63 and flow downalong the screen into the pool 58. l

Positioned a short distance within the stationary screen 63 is an annular filter element 64 which extends clear from the bottom wall 510i the ease up to the wall 62, so that all air passin through the annular screen 63 has to pass through the filter element. As clearly shown in the drawing, the filter element consists of two screen walls 85 and 66, respectively, containing therebetweena' mass of metal turnings, or the like, 61. As shown, the filter element 64 is thicker at the bottom than at the top, as this is sometimes found desirable, although it is not essential. v As the air carrying an excess of liquid in the form of mist or-droplets passes through the filter 64, the liquid is-trapped on the-surfaces of the filter elements together with the dirt and dust present, whereas the c ean air passes on through the filter element and into the top of a discharge pipe 68 which extends through the bottom wall 52of the case. The oil accumulating in the filter element 61 works it way downwardly by gravity carrying the accumulated dust and dirttherewith so that the filter element s being continually cleaned by the addition of oil and the dirt trapped is washed down into the pool and accumulates in the bottom of the case.

The skirt 5! preferably has an outwardly extending ridge or flange on its outer surface at a short distance above the oil level for preventing oil from creeping up along the outer surface of the skirt.

respectively,

uid and dividing the spacein saidcasingabove the liquid into inner and outer compartments, the inner compartmentbeing in a open communication with said gasco'nduit, means supporting said rotor for free rotation and means for rotating it, means defining passages in" said rotor for the flow of gas therethrough, the por tion of said rotor below said passages converging inwardly and downwardly into said liquid, where by rotation of the rotor forces liquidupwardly l l thereal-ong to said passages by centrifugal force,

' and means communicating with said outer com partment to complete a path for gas now through said cleaner.

2. A gas cleaner as described in claim Lin which said last-mentioned means comprises open ings in said casing, and means associatedwith said openings and responsive to gas flow there through for applying a torque to said rotor to rotate it. p l

3. A gas cleaner as described in claim 1, with means exteriorlof saidcasing for rotating said rotor, and vanes on said rotor forinducing flow of gas through said casing in response to rotation of said rotor.

4. Apparatus as described in claim 1, in which said'casing comprises a lower stationary member and detachable cover with said rotor rotatably supported from and removable with said cover.

,5. A gas cleaner as described in claim 1, in which said stationary casingcomprises a lower, open'top member anda detachable cover member, and said rotor has a supporting shaft, upper bearingmeans on said cover member for rotatably supporting the upper end or said shaft, a lower bearing member for'said shaft, and a spider freely slidable in said ga conduit for radially supporting said lower bearing.

6. 'A gas cleaner comprising a porous gas-ilk tering element adapted to be wetted with a cleaning liquid to make it effective, means defining a basin below said filtering element for containing a pool of said liquid,- arotor rotatable about a vertical axis and means for rotating it, said rotor having a downwardly converging annular wall member dipping into the liquid in said basin,

whereby liquid is elevated in a thin film along the surface of said annular wall member by centrifugal force in response to rotation or said rotor, said annular wall member having an opening therein above the liquid level insaid basin for passage of gas, and means for conducting a stream of gas to be cleaned first through said opening in said annular wall member to entrain liquid rising along the wall member to said opening, and then through said filtering element.

'7. A ga cleaner comprising a casing having a basin therein for containing a pool of liquid,

- means for conducting a stream of gas to be cleaned through said casing above said pool, a,

rotor rotatable about a vertical axis and means for rotating it, said rotor having a downwardly converging annular wall member dipping into the liquid in said basin, whereby liquid is elevated in a thin film along the surface of said annular wall member and discharged from the upper portion thereof by centrifugal force in response to rotation or said rotor, said liquid being discharged from said rotor into said gas stream, screen means in the path of said stream beyond the point of delivery into said stream of said liquid for subdividing liquid particles and intermixing said liquid and gas, said screen member being in the form of an annular wall positioned inwardly of said annular wall member, and means beyond said screen means for separating liquid particles from said gas stream and consisting of a relatively thick porous annular wall positioned inwardly of said screen.

8. A gas cleaner comprising a gas filter element adapted to be wetted with liquid to make it effective, means defining a basin below said filter element for containing a pool of liquid, a rotor rotatable about a vertical axis, said rotor having a downwardly converging annular wall member dipping into the liquid in said basin, said annular wall member having openings therein above the liquid level in said basin for passage of gas therethrough, vane means on said rotor responsive to gas fiow through said openings for rotating said rotor, whereby liquid is elevated in a thin film along the surface of said annular wall member by centrifugal force, said openings being in that portion of said annular wall member carrying said liquid film, whereby said liquid is discharged into said openings and entrained into gas flowing therethrough, and means for conducting a stream of gas to be cleaned first through said openings in said rotor and then through said filter element.

9. A ga cleaner comprising means defining a basin for containing a pool of liquid, a rotor rotatable about a vertical axis, said rotor havin a downwardly converging annular wall member dipping into the liquid in said basin and an annular porous section extending upwardly and outwardly from said annular wall member, and

'means for rotating said rotor whereby liquid is elevated in a thin film along the surface of said annular wall member and into the inner, lower edge of said porous section and thence outwardly through said porous section by centrifugal force, and means for conducting a stream of gas to be cleaned inwardly through said porous section.

ROBERT A. KELSEY. HARRY WRIGHT. 

